Secretagogue is one of those subjects where the details matter more than the headlines. This page pulls together the background, the mechanisms, and the practical points readers ask about most.
Last reviewed on 2026-06-20. Where a claim depends on a specific study, the study is described rather than over-claimed.
Human data remain limited and come mainly from small, short-term studies conducted decades ago. The peptide has not received approval as a medicine from major regulators, so current availability is largely as a research chemical. Reported effects on growth hormone pulsatility, appetite, and body composition should be read as preliminary, since few independent groups have replicated the original findings. Analytical characterization of research-grade material varies between suppliers, which complicates comparison across studies. Regulatory status also differs by country, and some jurisdictions classify it as a prescription-only or otherwise restricted item.
Ipamorelin is a synthetic pentapeptide that belongs to the growth hormone secretagogue class. It acts as an agonist at the ghrelin receptor, also called the growth hormone secretagogue receptor type 1a. The compound was designed in the 1990s during a search for agents that release growth hormone with fewer off-target hormonal effects than earlier secretagogues. It appears in the research literature under several sequence-based names. Material supplied for laboratory work is normally a lyophilized solid, and it is not marketed as an approved therapeutic in major jurisdictions.
The molecule contains five residues, including alpha-aminoisobutyric acid, D-2-naphthylalanine, and D-phenylalanine, and it ends in a lysine amide. Non-natural and D-configured residues make the chain less susceptible to common peptidases, which helps explain its resistance to rapid breakdown. Its molecular formula is C38H49N9O5, corresponding to a free-base mass near 711.9 daltons. The C-terminal amide removes a negative charge and is a recurring feature in receptor-active peptides of this family. These structural choices are usually discussed as the basis for its selectivity profile.
Selectivity is the property most often attached to this peptide. Published animal and early human studies record increases in growth hormone release after administration, with adrenocorticotropic hormone and cortisol responses remaining small by comparison. Effects on appetite-related pathways also appear weaker than those reported for several earlier secretagogues. Reviews that compare members of the growth hormone secretagogue family cite these findings frequently, though the receptor-level explanation for the selectivity continues to be debated rather than settled.
Ipamorelin is a synthetic pentapeptide classified as a growth hormone secretagogue. Its sequence, Aib-His-D-2-Nal-D-Phe-Lys-NH2, combines three non-proteinogenic residues with a C-terminal amide. The N-terminal aminoisobutyric acid unit and the two aromatic D-amino acids distinguish it from peptides assembled only from standard L-amino acids. Its formula is C38H49N9O5, corresponding to an average mass near 711.9 Da. At neutral pH the molecule carries a net positive charge, a property that shapes its behaviour in chromatographic and electrophoretic systems.
The compound was developed at Novo Nordisk during the 1990s as part of a programme seeking secretagogues with improved selectivity. It was described in the peer-reviewed literature in 1998 alongside related pentapeptides from the same series. Investigators advanced it because it raised growth hormone output in animal models while leaving other pituitary hormones comparatively unaffected. The development code NNC 26-0161 appears in earlier reports, and ipamorelin later became the common designation in published work.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C38H49N9O5 | Value for the free base |
| Molar mass | 711.9 g/mol | Calculated from the formula |
| Appearance | White to off-white powder | Typical lyophilized form |
| Mechanism class | Ghrelin receptor agonist | Also described as a secretagogue |
| Half-life | About 2 hours | Reported for human circulation |
Quality control for research-grade ipamorelin is not governed by a single harmonized pharmacopeial monograph, so certificates of analysis vary between suppliers. Common tests include appearance, solubility, water content, peptide content by quantitative amino acid analysis, and residual counterion measurement. Independent verification by an outside laboratory is often used to confirm identity and purity claims. Salt form, counterion content, and residual solvent levels are frequently unspecified, which complicates direct comparison between lots and leaves reproducibility partly unresolved.
Identity and purity assessment of ipamorelin relies mainly on reversed-phase high-performance liquid chromatography with ultraviolet detection near 214 nanometers, a wavelength where the peptide backbone absorbs. Mass confirmation is typically obtained by electrospray ionization mass spectrometry or by liquid chromatography coupled to mass spectrometry, comparing the observed mass with the calculated value. Amino acid analysis and peptide mapping after enzymatic digestion can confirm the sequence. Impurity profiles include deletion peptides, truncated fragments, and oxidation products, reported as relative area percentages.
Lyophilized ipamorelin is generally held at minus twenty degrees Celsius or colder, protected from light and moisture. In solution the peptide is less stable, and degradation proceeds through hydrolysis of the amide backbone, oxidation of the histidine residue, and aggregation. Repeated freeze-thaw cycles accelerate these processes, so dividing material into single-use aliquots before freezing is common practice in research settings. Buffered formulations near neutral pH tend to show the slowest degradation, while strongly acidic or basic conditions raise hydrolysis rates. Stability data specific to ipamorelin are sparse, and much guidance is extrapolated from other short peptides.
冻干状态下的肽通常比溶液状态更稳定，常规做法是维持 -20 °C 或更低温度、保持干燥并避开强光。复溶后的降解主要来自水解、氧化与脱酰胺，速率受 pH、缓冲液种类、离子强度与温度共同影响，碱性条件一般会加快这些反应。反复冻融会造成聚集与容器吸附损失，分装保存能降低该风险。容器材质与金属离子也可能参与氧化过程，需与操作条件一并考虑。
对 ipamorelin 的常规表征以反相高效液相色谱测定纯度，检测波长多设为 214 nm，因为肽键在该波长有较强吸收。身份确认通常借助电喷雾电离质谱或串联质谱，将实测分子量与理论值逐项比对。序列层面可用肽图分析或氨基酸分析进一步验证。这些手段组合起来，可以分别覆盖纯度、身份与序列三个不同层次的信息。
杂质谱一般包含缺失序列片段、差向异构体、氧化产物以及残留溶剂或反离子，其中组氨酸与芳香残基的氧化常被重点关注。反相色谱中这类杂质往往紧邻主峰洗脱，因此方法需要足够的分离度并经过系统适用性验证。纯度百分比的解读依赖于检测波长与梯度条件，不同实验室公布的数字不宜直接横向比较。参考标准品有助于跨批次对照，但其自身赋值同样需要可追溯来源。
Published discussion of this compound is uneven. Some references describe it as a tool for probing growth hormone regulation, while others focus on analytical characterization or on comparisons with related secretagogues. Statements about selectivity, half-life and potency often trace back to a small number of original reports that later authors cite secondhand. Readers evaluating a claim should therefore check whether a figure reflects a direct measurement or a repeated citation, and whether the underlying study was conducted in animals, in isolated cells or in human volunteers.
Identity and purity assessment for a research peptide of this kind typically combines reversed-phase high-performance liquid chromatography with mass spectrometry. The chromatographic run separates related impurities and yields a purity percentage, while electrospray ionization or matrix-assisted laser desorption mass spectrometry confirms the expected molecular mass. Amino acid analysis or tandem mass spectrometry sequencing can add confidence when material is intended for quantitative work. Laboratories differ in how they calculate and report purity, so figures from different sources are not always directly comparable.
Lyophilized material is generally stored cold and dry, with desiccant, and protected from light. In solution the peptide is more vulnerable: the histidine side chain can oxidize, and repeated freeze-thaw cycles promote aggregation and loss of material to container surfaces. A mildly acidic aqueous buffer is often used for short-term handling because it limits several degradation routes. Accurate prediction of long-term stability under a given set of conditions is difficult, and published stability data remain sparse.
Compared with older secretagogues such as hexarelin or GHRP-6, ipamorelin shows weaker stimulation of cortisol, prolactin, and appetite in the animal models used for early characterization. Whether that selectivity is preserved across longer human exposures remains an open question, because published clinical data are limited in size and duration. Reported effects on food intake are generally described as modest. The compound is therefore treated in the literature as a relatively selective research tool rather than a fully characterized therapeutic agent.
Ipamorelin is a synthetic pentapeptide that belongs to the growth hormone secretagogue class of compounds. Researchers at a pharmaceutical company first described it in the 1990s while screening small peptides for growth hormone releasing activity. Its chain contains five amino acid residues, two of which are non-natural building blocks, including 2-aminoisobutyric acid and a naphthylalanine derivative. The molecule was designed to act at the ghrelin receptor while avoiding several effects observed with earlier secretagogues.
At the cellular level, ipamorelin binds the growth hormone secretagogue receptor, also called the ghrelin receptor. Activation of this receptor on pituitary somatotroph cells triggers a signaling cascade that leads to release of growth hormone into circulation. Because release follows a pulsatile pattern, studies often report peak concentration and total area under the curve rather than a single time point. Selectivity for this receptor is the property most frequently discussed in comparative work.
On May 27, 2014, Mister Donut collaborated with the Japanese fast food franchise Mos Burger on the MOSDO!, a burger using "a spiral-shaped chorizo, lettuce and spicy chili sauce sandwiched between Mister Donut's French Cruller donut as the buns." The menu item was released at Mos Burger stores, while Mister Donut stores at the time were selling "Mos Burger's famous rice burger with sweet bean paste, sweet potato paste, and custard cream stuffing." In April 2015, Mister Donut released new items such as the "Brooklyn Merry-Go-Round, which uses both cookie and bagel dough." At the time, the company announced that it would "launch new key products quarterly while maintaining its standard menu." In 2015, Japan revealed a summer doughnut menu themed to Brooklyn, New York. Japan Times explained that the menu was "'Brooklyn themed' in the sense it combines several foodstuffs into one, in the style of New York-born fusion treats such as the Cronut." Items included "berry or lemon doughnuts cut in half, with a layer of yogurt added to the middle, or a chocolate option with sugary cream in the center." As of May 2016, "some 80% of the menu at Mister Donut bakery and cafe is made up of coffee drinks and the rest is doughnuts." In Japan, current items as of July 2016 may include the old-fashioned doughnuts covered in chocolate or cinnamon-flavored. There is also a "chocolate almond croissant muffin," a salty donut, a chocolate-covered churro, a financier donut, and a Japanese-style matcha kuromitsu stick.
== Further reading == Wainwright, Dylan K.; Lauder, George V. (2017). "Mucus Matters: The Slippery and Complex Surfaces of Fish" (PDF). In Gorb, Stanislav N.; Gorb, Elena V. (eds.). Functional Surfaces in Biology III: Diversity of the Physical Phenomena. Biologically-Inspired Systems. Vol. 10. Springer, Cham. pp. 223–246. doi:10.1007/978-3-319-74144-4_10. ISBN 978-3-319-74144-4. Retrieved 2021-09-13.
The elements on the periodic table were originally arranged in order of increasing atomic weight. However, in a number of places chemists chose to swap the positions of certain adjacent elements so that they appeared in a group with other elements with similar properties. For instance, tellurium is placed before iodine even though tellurium is heavier (127.6 vs 126.9) so that iodine can be in the same column as the other halogens. The modern periodic table is based on atomic number, which is equivalent to the nuclear charge, a change that had to wait for the discovery of the nucleus. In addition, an entire row of the table was not shown because the noble gases had not been discovered when Mendeleev devised his table.
In effect, the extremist Catholic and Orthodox forces were colluding in a bloody partition and cleansing of Bosnia-Herzegovina. They were, and still are, largely spared the public shame of this, because the world's media preferred the simplification of "Croat" and "Serb," and only mentioned religion when discussing "the Muslims." But the triad of terms "Croat," "Serb," and "Muslim" is unequal and misleading, in that it equates two nationalities and one religion. (The same blunder is made in a different way in coverage of Iraq, with the "Sunni-Shia-Kurd" trilateral.)
Specific impulses as high as 350 s (3.5 kN·s/kg) can be achieved, depending on the fuel. Peroxide used as an oxidizer gives a somewhat lower Isp than liquid oxygen but is dense, storable, and non-cryogenic and can be more easily used to drive gas turbines to give high pressures using an efficient closed cycle. It may also be used for regenerative cooling of rocket engines. Peroxide was used very successfully as an oxidizer in World War II German rocket motors (e.g., T-Stoff, containing oxyquinoline stabilizer, for both the Walter HWK 109-500 Starthilfe RATO externally podded monopropellant booster system and the Walter HWK 109-509 rocket motor series used for the Me 163B), most often used with C-Stoff in a self-igniting hypergolic combination, and for the low-cost British Black Knight and Black Arrow launchers. Presently, HTP is used on ILR-33 AMBER and Nucleus suborbital rockets. In the 1940s and 1950s, the Hellmuth Walter KG–conceived turbine used hydrogen peroxide for use in submarines while submerged; it was found to be too noisy and require too much maintenance compared to diesel-electric power systems. Some torpedoes used hydrogen peroxide as oxidizer or propellant. Operator error in the use of hydrogen peroxide torpedoes was named as possible causes for the sinking of HMS Sidon and the Russian submarine Kursk. SAAB Underwater Systems is manufacturing the Torpedo 2000. This torpedo, used by the Swedish Navy, is powered by a piston engine propelled by HTP as an oxidizer and kerosene as a fuel in a bipropellant system.
Sources: en.wikipedia.org
After the Rollercoaster Tour to support the album, the band concentrated on cracking the United States' market, with an appearance on David Letterman's show, and a tour as part of the Lollapalooza line-up, which William later described as "the worst experience of our lives," followed by their own headlining tour. In December 1992, the Reids again lost their rhythm section, with Ben Lurie returning and Steve Monti joining on drums. Another compilation was released in 1993, The Sound of Speed, before they returned to the studio to record their fifth album proper, Stoned & Dethroned which would see release in 1994, and featured guest appearances from Shane MacGowan and William's then-girlfriend Hope Sandoval. The album was originally planned as an acoustic album, but this idea was abandoned because, in Jim's words, "We couldn't do enough interesting things with acoustic guitars to make an album". In the 1995 EP released under American Records, a number of new works and B-sides were published which were later collected in the album Munki. After the release of the 1995 compilation Hate Rock 'N' Roll, the Mary Chain parted ways with Blanco y Negro, their record label of over a decade, and re-signed to their original label Creation Records, and Sub Pop in America. The band now included former Lush bassist Phil King. They then recorded 1998's Munki album, which would turn out to be their last before splitting the following year. Munki was commercially the least successful album the band released, peaking at number forty-seven in the UK Album Chart.
=== Elsewhere === Generally, the firmer styles of tofu are used for kebabs, mock meats, and dishes requiring a consistency that holds together, while the softer styles can be used for desserts, soups, shakes, and sauces. Some people enjoy tofu made and prepared with chocolate and making it into pies and mousse along with other tofu desserts. This came about due to vegans and vegetarians avoiding the usage of items such as milk and eggs. Firm Western tofu types can be barbecued since they hold together on a barbecue grill. These types are usually marinated overnight as the marinade does not easily penetrate the entire block of tofu. (Techniques to increase the penetration of marinades include stabbing repeatedly with a fork or pressing out the initial water content either by hand or with a tofu press prior to marinating. Before pressing the tofu, it is sometimes frozen and thawed in order of creating a more porous texture, often compared to a sponge. This texture does not only help release the initial water content, but also allows for an altered mouthfeel and more absorbent structure. Typically, the tofu is frozen and thawed once, although some culinary experts recommend executing this technique twice for a stronger effect.) Grated firm Western tofu is sometimes used in conjunction with textured vegetable protein (TVP) as a meat substitute. Softer tofus are sometimes used as a dairy-free or low-calorie filler. Silken tofu may be used to replace cheese in certain dishes, such as lasagna.
They have improved a process from Monsanto by using ultrafiltration to concentrate the incoming lignosulfonates, which reduces the amount of NaOH used and waste produced. The basic chemistry is unchanged: alkaline oxidation using a metal catalyst such a copper salt. According to Scientific American, vanillin produced this way contains aromatic impurities that add strength and creaminess to its flavor. This is probably due to acetovanillone being present.
== Further reading == Andersen, O.M. (2006). Flavonoids: Chemistry, Biochemistry and Applications. Boca Raton FL: CRC Press. ISBN 978-0-8493-2021-7. Gould, K.; Davies, K.; Winefield, C., eds. (2008). Anthocyanins: Biosynthesis, Functions, and Applications. Springer. ISBN 978-0-387-77334-6.
== Distribution == The chain catshark is found in the Northwest Atlantic, Gulf of Mexico and Caribbean, ranging from George's Bank in Massachusetts, to Nicaragua and Barbados. In the Mid-Atlantic Bight, the chain catshark is found along the outer continental shelf and upper slope. The shark occupies depths of 36 to 750 meters (118–2,461 ft); in the northern part of its range it is mainly found between 36 and 230 meters (118–755 ft) and in the southern areas generally deeper than 460 meters (1,510 ft). Due to the shark's depth distribution, it has been suggested that the shark does not perform large-scale migrations. Temperature is thought to limit the shark's distribution in northern areas, particularly during the winter. Although bands of warm water at the edge of the shelf have been observed, the temperature varies seasonally, thus limiting this non-migratory species. In general, the chain catshark is found in waters with a temperature between 8.5 °C (47 °F) and 14 °C (57 °F).
Sources: en.wikipedia.org
It has not been approved as a therapeutic by major regulators, and the human trial record is small and dated. Material available today is mostly sold as a research chemical for laboratory use. Approval and restriction status varies by country.
It binds the ghrelin receptor, known as the growth hormone secretagogue receptor type 1a. Activation of that receptor triggers signaling that leads to growth hormone release. Selectivity for growth hormone over cortisol and prolactin is the property most often cited for this compound.
Published estimates place the circulating half-life at roughly two hours in humans. Clearance involves peptidase activity and renal handling. Because the peptide is short-lived, release patterns after administration are usually described as pulsatile rather than sustained.
It is a synthetic five-amino-acid peptide that acts as a growth hormone secretagogue. Three of its residues are non-standard amino acids, and the chain ends in an amide rather than a free acid. The molecule is small enough that it can be characterised by routine peptide analytical techniques.